The Pantheon, designed by the architect Apollodorus of Damascus under the command of Emperor Hadrian between 118 and 128 AD .

The wall that supports the building at its base reaches 6 meters thick, while the dome is lightened getting on top to have "only" 1.5 meters thick. The dome is supported by a cylindrical drum, its height being equal to its diameter, can be constructed, therefore, inside the building, a virtual sphere diameter 43.4 m.